ACA at dawn

360 degree panorama view of the Atacama Compact Array (ACA) on the ALMA high site at an altitude of 5000 metres in northern Chile. The ACA, or Morita Array, is a subset of 16 closely separated antennas that will greatly improve ALMA’s ability to study celestial objects with a large angular size, such as molecular clouds and nearby galaxies. The antennas forming the Atacama Compact Array, four 12-metre antennas and twelve 7-metre antennas, were produced and delivered by Japan.